“Breaking Through Time: Scientist Unravels a Puzzling Time-Travel Conundrum”

Due to the unchangeability of this fact, numerous physicists argue that rising entropy dictates the ‘arrow of time,’ or the course in which time unfolds, as opposed to time dictating an increase in entropy. Indeed, Gavassino mentions in his paper that “entropy increase is the sole physical law that allows us to make a fundamental distinction between past and future.”

The second essential principle in Gavassino’s endeavor to nullify the paradox is the closed timelike curve. Initially conceived as a result of Einstein’s general theory of relativity, closed timelike curves are the theoretical outcomes of rotating gravity wells being capable of effectively dragging spacetime (the amalgam of space and time) along with their movement. We frequently observe unusual effects of gravity on spacetime around phenomena like black holes, but if you take the idea that gravity could pull spacetime around to its ultimate conclusion, a spinning gravity well could eventually cause time to flow in a circular manner. That circle is a closed timelike curve, or CTC, which could theoretically be traversed to return to an earlier time. After all, if time is circular, you could advance into the future for a prolonged period and end up back in the past, before where you originally began.

But, wait a minute. If you initially travel forward in time, you are moving in the direction of rising entropy. And if you somehow end up back in time, you would have had to reverse entropy. Which is unfeasible… right?

Perhaps not. The overarching conclusion of Gavassino’s research is that CTCs operate not like endless loops, but resemble two half-circles, each commencing and concluding at the points on the CTC with the least and most entropy, respectively. This might appear contradictory to many of the claims we’ve made up to this point until we introduce the third and final concept necessary to unify this entire argument—quantum physics.

Although we might observe the impacts of classical physics most prominently in our daily lives, we exist in a quantum universe, and quantum governs all (even in manners we have yet to comprehend). The quantum domain abides by what is known as a “self-consistency principle” which, as per the paper, means “the only histories of the Universe that truly occur are those where everything resolves consistently.” Gavassino posits that this principle would essentially ensure that any alterations made to the past during a time-traveling excursion wouldn’t ‘stick,’ thereby permitting the two-half-circle CTC to operate without violating entropy laws and effectively erasing nearly any time-travel paradoxes that might arise. Essentially, you couldn’t kill your grandfather because you exist. And if you did, it wouldn’t be viable.

Gavassino asserts that this could have a tremendous number of implications, including de-aging, “spontaneous memory loss,” and a complete inability to encounter your younger self by returning to the past. However, to clarify, all of this depends on the very hypothetical existence of CTCs which Gavassino does not endeavor to prove or assert in his research.

So, intriguing? Indeed. But we still have a significant distance to cover—and will need considerable luck with the realities of a few yet-to-be-understood laws of physics—before it becomes genuinely worth concerning ourselves with the consequences of, say, stepping on a butterfly and ceasing to exist.

Jackie is an author and editor hailing from Pennsylvania. She has a particular fondness for writing about space and physics, and enjoys sharing the unusual marvels of the universe with anyone eager to listen. She is overseen in her home office by her two cats.